Safety gas cock



March 25, 1930. w. VAHL SAFETY GAS COCK Original Filed Jan. 14, 1928 Iwl lhrlJ laL I Inventor WHliam Vahl By I M Atlomey Patented Mar. 25,1930 UNITED STATES WILLIAM VAHL, OF ROCHESTER, NEW YORK SAFETY GAS COCKApplication filed January 14, 1928, Serial No. 246,825. Renewed January13, 1930.

This invention relates to thermostatic gas shut-off mechanism forautomatically controlling a gas shut-off valve and the invention has forits object to provide a simple, inexpensive and efficient apparatus thatcan be readily attached to the ordinary gas burner so that the flow ofgas to the burner is automatically shut off whenever the burner flame isaccidentally extinguished.

This and other objects of this invention will be fully illustrated inthe drawing, described in the specification and pointed out in theclaims at the end thereof.

In the accompanying drawing:

Figure 1 is a side elevation of the thermostatic gas shut-off mechanismas it appears when attached to an ordinary gas burner.

Figure 2 is a top plan view of the thermostatic shutoff mechanism andgas burner to which it is attached.

In the several figures of the drawing like reference numerals indicatelike parts.

The apparatus forming the subject matter of this invention is bothsimple in construction and operation and is mace so as to be readilyapplicable to all types of gas burners such as are used in gas stoves,gas heaters etc. where it is desirable to have the gas supplyautomatically shutoff whenever the burner flame is accidentallyextinguished. The

manufacturing cost of the apparatus is furthermore small so that itssales price will not make the use of the apparatus prohibitive.

As'illustrated in the figures of the draw- 5 ing, the supporting frame 1is bent up of sheet metal and its forward end engages and is supportedby the gas supply pipe or the shut-off valve 2. The rear end of theframe 1 is supported by the clamp 3 which is at- 43 tached to the insideof the frame 1 and fastens around the inlet of the gas burner 4. Theframe 1 extends along one side of the gas burner so that the movingparts of the apparatus can be readily mounted thereon with- '5 outinterference with the operation and use of the burner. V

The thermostatic needle 5 which controls the opening and closing of theshut-off valve 2 is mounted on the vertical circular plate 7 :0 which isfastened to the right hand end of the frame 1 by means of suitable bolts8, 8. This needle is made up in the form of a flat spring and its upperend is suitably anchored on the outer side of the plate 7 to allow thebody of the needle to freely flex back and forth on the heating andcooling of it. At the lower end the thermostatic needle 5 carries thepin 9. This pin passes thru the slot 10 provided in the rear end of thelink 11 and is held in engagement in the slot by a suitable washer 12 0that is fastened to the outer end of the pin. The slot is enlarged atthe left hand end and a shoulder 13 is formed by this enlargement at theupper edge of the slot. On theheatof the thermostatic needle by theflame of the gas bruner the needle flexes to the left so that the pin 9slides forward in the slot 10 until it has reached the enlargement of itwhich allows the link to drop so that the pin engages behind theshoulder 13.

The left hand end of the link 11 is pivotally attached to the arm 14projecting from the periphery of the mutilated gear 15. This gear ismounted to oscillate on the pin 16 one end of which is pivotally mountedin a bearin in the bracket 17 that is fastened to the frame 1, and theother end of which is mounted in a bearing formed in the frame 1 proper.A station ary pin 18 extends between the bracket 17 and the frame 1close to the perimeter of the mutilated gear 15 and between the teeth 19and. 20 that project from the periphery so that the 1110\:;'i1111t ofthe mutilated gear is limited by the distance be tween the teeth 19 and20 and the engagement of the pin 18 with either of these teeth. Theseries of consecutive teeth 21, 21 are adapted to mesh with the pinion22 which is carried on the shaft 23. This shaft is mounted to rotatebetween the bracket 17 and a suitable bearing provided in the body ofthe shut-off valve 2. On the shaft 23 is also mounted the eccentric 24so that it will rotate whenever the pinion 22 is rotated by themutilated gear 15. '95 The handle 25 of the shut-off valve 2 is normallyheld in a closed position by the coil spring 26 which encircles aportion of the body of the valve and has one end anchored thereto whilethe other end is anchored to we the handle 25. To the bottom of thevalve is fastened the ratchet wheel 27 which is provided with but oneratchet tooth 28 in the perimeter thereof. On the body of the shut offvalve is also provided a bracket 29 which carries the pivot pin 80 onwhich the curved so that gas is supplied to the burner thru itsregulatingvalve 32.

When the gas passing thru the burner is ignited, the flame of the burnerheats the circular plate 7 and the thermostatic needle 5 mountedthereon. This causes the needle to flex to the left as above describedso that the pin carried at the bottom of the thermostatic needle movesin the slot 10 behind the shoulder 13 provided therein. As long as theflam of the burner keeps on burning the different parts of the mechanismwill be in the position illustrated in the figures except that the pin 9carried by the thermostatic needle is moved in place behind the shoulder13 of the slot 10 as above pointed out.

When, however, the flame of the burner is accidentally extinguished, thethermostatic needle will quickly cool off and in so doing flex back tothe right. As it flexes back, the needle will pull the link 11 with itby reason of the engagement of its pin 9 with the shoulder 1 3. Therearward movement of the link .11 turns the mutilated gear 15 throughthe :1111114 which in turn rotates the pinion 22 and the eccentric 24.The movement of he eccentric 24 against the rear end of the pawl levercauses the pawl 31 to disengage from the ratchet tooth of the ratchetwheel so that the spring tension of the coil spring 26 is w free to turnthe handle 25 of the shut oil valve and close the valve. In this way theextinguishing of the flame of the burner will cause the shut off valveto be closed so that no more gas can flow to the burner until theshutoff valve is manually operated to open the valve.

In order to disengage the pin 9 of the thermostatic needle from theshoulder 13 after the shut off valve has been operated, the rear end ofthe link 11 is provided with the inclined cam surface 33 which isadapted to slide up on the pin 3d on the rearward motion of the link.The pin 84 is anchored in the circular plate 7 and as the inclined camsureccentric surface away from the end of the pawl lever untilit isagain brought in contact therewith the nextytime the shut-off valve isturnedon and the pawl 31 can engage theratchet tooth of the ratchetwheel.

I claim: 1. In an automatic shut-0d mechanism for gas burners, thecombination with a burner and a regulating valve, of a shut-off valve, a

supporting frame supported by said burner,

a vertical heating plate carried by said supporting frame at one endthereof and held on one side of the burner, a thermostatic needlemounted on the side of said vertical heating plate, a ratchet wheelcarried by said shut-off valve, a pawl adapted to engage said ratchetwheel and hold said shut off valve in the open position, an eccentricadapted to engage said pawl and means for rotating said eccentric torock said pawl and release said ratchet and said shut off valve, springmeans adapted to operate said valve on the release of said ratchet,means for rotating said eccentric, a connecting link connecting saidrotating means with said thermostatic needle, said link having a slottherein, a shoulder formed in the upper edge of said slot, a pin carriedat the lower end of said thermostatic needle and engaging into said slotin said link and adapted to be moved in said slot into engagement behindsaid shoulder to pull said link on the flexing of said needle in onedirection, and means adapted to automatically disengage said pin fromsaid shoulder in said slot at the end of the movement of said linkcaused by the flexing of said needle.

2. In an automatic shut-.ofi mechanism for gas burners, the combinationwith a gas burner of a shut-off valve, a ratchet wheel carried on saidvalve, a pawl engaging said wheel to lock said valve'in open position,means for closing said valve on the release of said ratchet wheel, athermostatic needle, a mutilated gear having an arm thereon and a linkconnected thereto and a pinion meshing with said gear by which themovement of the thermostatic needle is transmitted in one direction tosaid pawl.

In testimony whereof I affix my signature.

WVILLIAM V 'VAHL.

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